复合材料细观结构三维有限元网格模型的建立

提出了针对颗粒夹杂为椭球形状并呈随机分布的多相复合材料的三维有限元网格的建立方法,为复合材料细观结构研究提供了一种全自动的建模工具。引入了以体积为标度的任意两椭球骨料侵入的判别准则,实现了一种三维随机骨料的投放算法;在基于映射法的颗粒表面有限元网格生成算法中通过扫描线布点和局部连接技术较好地解决了网格极化现象;采用改进的三维AFT方法生成基体的四面体网格,并利用AFT特性一次生成所有颗粒夹杂的四面体网格;为进一步的复合材料细观结构与宏观力学性能的多尺度计算打下了基础。最后用几个算例验证了算法的有效性。

THE CONSTRUCTION OF THREE-DIMENSIONAL FINITE ELEMENT MESH FOR MICROSTRUCTURE OF MULTIPHASE COMPOSITES

A method of three-dimensional finite element mesh generation for the multiphase composite with randomly distributed grain is presented, and an automatic modeling tool is given for the research of microstructure using FEM. The criteria of conflict overlap of any two ellipsoidal aggregates are proposed based on a volume-index, and a numerical method of three-dimensional random aggregate model is realized. The polarization of mesh is resolved in the finite element surface mesh generation based on traditional mapping approach coupled with local connection approach. The three-dimensional AFT method is improved to generate tetrahedron mesh of matrix and grains. By utilizing the characteristics of AFT, all the grains are meshed to tetrahedrons at one time. The proposed method lays down the foundation for further multi-scale computation between microstructure and macro-mechanical performances of the multiphase composite. Some examples are given to demonstrate the validity of the method.